Notes on Productivity Home Page

I'm exploring an idea for a specific demo for my Lotusphere presentation with David Allen. I normally try to find my own answers before I ask others or blog. but I'm running into roadblocks trying to find the answers to my questions. With the holidays approaching, I'm also running out of time.

So, here's my question to the ND community.

I want to be able to demonstrate two BlackBerry Bolds (already purchased) connected to Domino with
        a) custom applications and
        b) SameTime mobile.

We are a small consulting firm; I don't want to invest the resources to purchase a full Enterprise BES server just to support 2-3 demo users so that I can show my clients. There must be an easier (read: faster and low cost) way...

As best as I can tell, I will need:

1. A BlackBerry professional server of some flavor

2. MDS Support for the custom apps, and possibly for the Mobile SameTime
        (Isn't there a simple way to just connect SameTime to the server direct?)

It appears that my initial options are:

Blackberry Professional Express.
        Great for messaging only
        Does not appear to support MDS or SameTime
        Free for first user, ~$100 for each additional user

BlackBerry Professional Software
        See here for comparison
        Appears to support MDS, though not stated
        SameTime support not available (Unless I can manually load)
        Will cost me $500 for my 2 users (up to 5)

BlackBerry Enterprise server
        See here for comparison
        Will support MDS and Enterprise IM (SameTime)
        Will cost me $4000 for my first 2 users (up to 20)
        $ out of my ball park for a demo.

Hosted Options
        I've sent email to one hosting company; but I have no idea of price or time to deploy.
        It appears it will take weeks to get set up, which may be a deal breaker
        Security?

As you can see, I know what I want to accomplish. If this were for a client, I would opt for the full enterprise sever. For my own test, demo, and development, that's a bit steep. All I really care about is the ability to use and demo this at Lotusphere. So I need to get it set up quickly, load up a few custom apps and SameTime, if at all possible) and go. I would be most appreciative to talk with some who's been down this path before and who has set up this specific type of system. Thanks folks.